1. Urban Ecosystems

2. How does a city get started? Usually an historic trade route or location near some valuable resource, e.g. water Usually without any long-term planning Usually in an area where it is easiest to build structures, e.g. flat or gentle terrain (interesting exceptions – San Francisco!)

3. How is a city structured?

4. Most are structured through historical “accidents” Most do not have large, open “green spaces” Zoning has segregated living areas from business areas to some extent

5. What problems have developed because of these structures?

6. Problems with water Runoff is usually polluted. With what? Urban runoff – fast, furious with little percolation. Why? Urban flooding results from this.

7. Some possible solutions from the Los Angles Demonstration House

8. Cisterns for collecting rainwater

10. Vegetated Swales for moving water and retaining it within specified areas

11. In this case, they used mulch rather than vegetation

12. Retention Structures

14. Driveway Collection ‘Well’

16. What problems have developed because of these structures?

17. Problems with air Air quality is bad in cities due to –Automotive sources –Industrial sources –Smoke from other sources Air quality is also bad due to lack of absorbing surfaces

18. What problems have developed because of these structures?

19. Urban Heat Island Effects

20. Suburban day Suburban day Suburban night Urban day Urban day Urban night Atlanta, GA

21. 1973 1976 1983 1987 1992 1997 Atlanta, GA

22. 1971 1997